The Yellow Knight / Summer / Autumn / Toxic
The Yellow Knight, Canary Mushroom, Man on Horseback.
They are mycorrhizal, mostly with pines but occasionally oak and birch. Most common in Scotland and Northern England.
A fairly common mushroom in pine plantations, it was once considered to be a good edible but recent studies have found it to be poisonous.
Bright yellow in colour, with a scaly or fibrous central area that is often slightly raised. They tend to have wavy, uneven margins. The cap skin is sticky when fresh and can be peeled off.
Pale yellow to white, it has light brown fibres running vertically towards the base.
The gills are pale yellow to white and are adnexed.
No real smell.
They were considered a good, tasty edible in the past and they do still sometimes appear on French market stalls, they are now thought to be toxic although there is some debate.
A Chinese study found that the Grey Knight contains toxins that cause a disease called Rhabdomyolysis, which is normally caused by serious muscle trauma for example being crushed or being bitten by a snake. It causes your muscle fibres to die, releasing their contents into your blood stream, this can lead to serious kidney failure. I have however also read reports that say that only eating what they call an ‘abnormal’ amount would cause rhabdomyolysis, they say that eating up to 200 grams per serving would be safe.
Other members of the Tricholoma family most likely The Sulphur Knight (Tricholoma Sulphureum) this mushroom also has a yellow cap, but it lacks the brown scales/fibres and it smells chemically like sulphur.
Medieval Knights apparently reserved Yellow Knights for themselves (which is probably where their common name comes from) they would leave the Bovine Boletes (Suillus Bovinus) for the peasants.